Method of preserving combustion chambers of engine from corrosion during storage



June 8, 1965 D. N. DIETZ- ETAL METHOD OF PRESERVING COMBUSTION CHAMBERS OF ENGINE FROM CORROSION DURING STORAGE Filed Sept. 26, 1962 United States Patent The present invention relates to a process for inhibiting corrosion, and more particularly to a new andimproved process which prevents the corroding of internal surfaces of internal combustion engines during storage and during periods of prolonged non-use.

In the past it has been known to spray preservative oil in through the spark plug hole of a spark ignition engine, or in through the precombustion chamber of a compression ignition engine to form an oil film upon the interior surfaces of the engine. In practice this method has proved to be less than satisfactory in that it is timeconsuming to remove the spark plugs or the glow plugs and injection nozzles from the engine, and also difficult to direct the spray of the preservative oil through a small restricted opening, Furthermore, it has been observed that the oil film thus produced breaks down after a period of time, and the water vapor contained in the entrapped air eventually condenses and corrodes the exposed surfaces. It has also been noted that the aforedescribed process has exhibited a tendency to force preservative oil droplets out the exhaust valves, and thus allow the entry of new air into the interior of the engine which contains condensible water vapor.

Another method, which has been commonly used to prepare diesel engines for storage, is to slowly stop the engine during the diesel cycle to allow a supply of unburned fuel to become sprayed upon the internal engine surfaces. This method has proven unsatisfactory in that it is diflicult to prevent the engine from self-igniting after .the' compression stroke, and thus the amount of unburned fuel is limited, and in fact corrosion producing products of combustion including water vapor are often present. Also, each of the cylinders will contain a volume of air, which will inclure condensible water vapor.

The general purpose of the present invention is therefore to provide a corrosion inhibiting process which is easy to practice, and which will effectively reduce the tendency of rust to accumulate upon the inaccessible surfaces on the interior of an internal combustion engine or the like, while obviating the difficulties encountered in the practice of prior art processes. To attain this, the present invention contemplates the introduction of an inert gas into the interior of an internal combustion engine, forcing the inert gas throughout the entire interior of the internal combustion engine, and retaining the inert gas in the said interior for the length of time it is desired to preserve the interior surfaces.

An object of the present invention is to provide a corrosion inhibiting process in which combustion is immediately stopped, so as to prevent the accumulation of corrosion producing products of combustion within the interior of an internal combustion engine. 7

Another object of the present invention is to provide a corrosion inhibiting process in which all water, oxygen, exhaust gases, and other corrosion causing. materials are removed from the interior of an internal combustion engine by the introduction of an inert non-corrosive gaseous agent.

A further object is to utilize the inertia of a moving engine to force inert gas through the intake, combustion, and exhaust systems of an internal combustion engine "ice to prevent corrosion from forming on the internal surfaces thereof.

A still further object of the invention is to provide dual protection from corrosion for the internal surfaces on an internal combustion engine by providing a protective film coating for the said surfaces while retaining an atmosphere of dry inert gas.

Other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the annexed drawing, which illustrates a preferred embodiment of the apparatus by which the present invention maybe practiced.

Refer-ring now to the drawing, reference numeral 10 is used to indicate a cylindrically shaped tank containing a supply of inert gas. Inert gases for the purposes of the present invention include those gases which are complete- 1y chemically non-reactive such as, argon, krypton, neon,

and xenon, and also those gases which are chemically non-reactive under the expected environmental conditions, such as nitrogen. The inert gas is retained within tank 10 under a high pressure, and when it is desired to use the apparatus, valve 11 is released to introduce a supply of gas into the system. A conventional pressure regulator 12, having the usual pressure and flow gauges 13 and 14, is provided in the system adjacent tank 10, and is adapted to control and limit the pressure of the inert gas to a maximum level, such as, for example, 100 lbs. per square inch. A relief valve 15, which is actuatable ata set predetermined pressure such as 120 lbs. per square inch, is provided in the system adjacent regulator 12 to act as a safety device. A flexible hose 16 extends from relief valve 15'to a T-fitting 17 that communicates with an accumulator tank 18, which is adapted to be charged with a supply of inert gas from the tank 10. A pressure gauge 19 is connected in the system adjacent accumulator 18, and is suitably provided with a pressure relief valve 20. A shut-01f valve 21 is provided in the system adjacent gauge 19, and is connected by a flexible hose 22 to a funnel 23 which is utilized to convey the inert gas into the air intake 24 of the engine to be preserved.

When it is .desired to preserve or store an engine the engine is either rotated under its own power or driven by external means, and while so rotating, valve 11 is opened to enable the inert gas to flow from tank 10 to accumulator 18. Cook 21 is then opened, and the inert gas flows through hose 22 and funnel 23 into the interior of the engine through air intake 24.

When the inert gas is introduced into a running internal combustion engine, the gas will quickly become dispersed throughout the entire interior of the engine and almost immediately stop combustion due to the exclusion of oxygen. Although combustion is not possible due to such circumstances, the inertia of the moving parts of the engine will force the inert gas into all of the inaccessible voids in the intake, combustion, and exhaust systems of the engine. It should also be noted that as the inert gas is forced throughout the interior of the engine, all corrosion causing agents such as water, oxygen, and exhaust gases are driven out through the exhaust system. The air intake and exhaust pipe of the engine can be then [suitably sealed to retain the corrosion inhibiting atmosphere of inert gas within the interior of the engine.

The process of the present invention has a further advantage in that as the inert gas is introduced into the interior of the engine, fuel becomes admixed therewith, and sets up a protective coating upon the internal surfaces. Some unburned fuel will likely passout the exhaust valve and coat the valves, manifold, exhaust pipe, muffler and tailpipe. While the dual protection as set forth above will have greatest utility in'diesel engines where a film forming fuel is used, it should be noted that the dual protection may also be provided in spark ignition engines,

since preservative materials may be added to the fuel before it is introduced into the engine. In this respect it should also be noted that when it is desired to preserve an engine which utilizes a volatile fuel, it may be desirable to add a vapor corrosion inhibiting agent into the fuel before it is introduced into the engine.-

While it is contemplated that the distribution of the inert gas throughout the interior of the engine will normally be accomplished by the inertia of the moving engine parts, it should also be observed that this may be accomplished by turning the engine over with the starter, by turning the engine over with an external power source, or by even manually rotating the engine crankshaft. Depreservation of an engine preserved by the present process is accomplished by merely removing the barriers from the tailpipe and air intake and turning the engine over to flush the inert gas from the interior.

As an illustration of the above process a direct starting six-cylinder diesel engine was tested. The engine was allowed to run at a no-load speed of 2100 rpm. and inert 7 gas was introduced into the engine through its air intake.

Combustion was stopped immediately as shown by the discharge of a white vapor from the exhaust, instead of the usual black combustion gases, and the engine completed 36 inertial revolution in .07 minute, using 18 cubic feet of nitrogen to flush the corrosion producing materials from the inaccessible voids in the interior of the engine.

The corrosion inhibiting tendencies of the present invention will be best understood from the tests hereinafter set forth illustrating one embodiment of the present invention:

Example 1 A six-cylinder spark ignition engine using ordinary gasoline as a fuel was run at 1050 r.p.m. for 35 minutes. The engine was then conventionally stopped without adding any preservatives into the interior of the engine. All entries to the manifold systems and water jacket were immediately sealed with two or more layers of pressuresensitive tape, and the engine was put on a rack, shrouded with reinforced asphalt laminated paper, and placed on a wooden pallet outdoors in an unsheltered area.

Example 2 A six-cylinder spark ignition engine, identical to the engine of Example 1, using ordinary gasoline as a fuel, was run at 1050 r.p.m. for 35 minutes. Dry nitrogen was then introduced to the intake manifold through the carburetor by manually applying the funnel 23 to the carburetor air-intake port. The engine stopped eleven revolutions after application of the inert gas. All entries to the manifold system and water jacket were immediately sealed with two or more layers of pressure-sensitive tape, and the engine was then put on a rack, shrouded d with reinforced asphalt laminated paper and placed on a wooden pallet outdoors in an unsheltered area.

After over eight months exposure both engines of Examples 1 and 2 were brought indoors, allowed to come to room temperature, and were inspected. As could be expected, the exposed unpainted surfaces of both the pre served and unpreserved engines were heavily rusted. All of the cylinder walls of the unpreserved engine of Example 1 also were rusted, the rust varying in intensity from light to heavy. However, the cylinder walls of the preserved engine of Example 2 were generally clean and free from rust, and the internal surfaces were in such condition that the engine was ready for immediate use.

These results illustrate the advantages to be obtained in preserving internal engine surfaces with an inert gas, and it will readily be appreciated that the present invention admirably fulfills all of its objects. Obviously many modifications and variations of the present invention are possible in the light of the above disclosure. Anyone skilled in the art of preserving machinery can readily see that this method could equally preserve compressors, pumps, steam engines, and turbines or the like, having difficultly accessible voids and moving valves or closures to control flow of gases. It is therefore to be understood, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. The method of inhibiting corrosion on the interior surfaces of an internal combustion engine during storage comprising the steps of: introducing a dry inert gas into the interior of a running internal combustion engine 0 through the air intake of said engine, said inert gas becoming intimately admixed with the engine fuel as it enters said engine, forcing said inert gas throughout the interior of said engine soas to inherently stop the engine by purging oxygen so as to prevent further combustion, said inert gas-purging the corrosion producing materials as it is dispersed into said interior, said engine fuel becoming coated upon said internal surfaces as said inert gas is forced throughout said interior, and retaining said inert gas and admixed fuel in said interior whereby corrosion on said internal surfaces is prevented.

2. The method set forth in claim- 1 wherein said inert gas is nitrogen.

References Cited by the Examiner UNITED STATES PATENTS- 1,817,714 8/31 Shand 212.5

6/60 Barker 123--1 

1. THE METHOD OF INHIBITING CORROSION ON THE INTERIOR SURFACES OF AN INTERNAL COMBUSTION ENGINE DURING STORAGE COMRPRISING THE STEPS OF: INTRODUCING A DRY INERT GAS INTO THE INTERIOR OF A RUNNING COMBUSTION ENGINE THROUGH THE AIR INTAKE OF SAID ENGINE, SAID INERT GAS BECOMING INTIMATELY ADMIXED WITH THE ENGINE FUEL AS IT ENTERS SAID ENGINE, FORCING SAID INERT GAS THROUGHOUT THE INTERIOR OF SAID ENGINE SO AS TO INHERENTLY STOP THE ENGINE BY PURGING OXYGEN SO AS TO PREVENT FURTHER COMBUSTION, SAID INERT GAS PURGING THE CORROSION PRODUCING MATEIALS AS IT IS DISPERSED INTO SAID INTERIOR, SAID ENGINE FUEL BECOMING COATED UPON SAID INTERNAL SURFACES AS SAID INERT GAS IS FORCED THROUGHOUT SAID INTERIOR, AND RETAINING SAID INERT GAS AND ADMIXED FUEL IN SAID INTERIOR WHEREBY CORROSION ON SAID INTERNAL SURFACES IS PREVENTED. 